The use of inkjet printers for printing information on recording media is well established. Printers employed for this purpose can include continuous printing systems which emit a continuous stream of drops from which specific drops are selected for printing in accordance with print data. Other printers can include drop-on-demand printing systems that selectively form and emit printing drops only when specifically required by print data information.
Continuous printer systems typically include a printhead that incorporates a liquid supply system and a nozzle plate having a plurality of nozzles fed by the liquid supply system. The liquid supply system provides the liquid to the nozzles with a pressure sufficient to jet an individual stream of the liquid from each of the nozzles. The fluid pressures required to form the liquid jets are typically much greater than the fluid pressures employed in drop-on-demand printer systems.
Particulate contamination in a printing system can adversely affect quality and performance, especially in printing systems that include printheads with small diameter nozzles. Particulates present in the liquid can either cause a complete blockage or partial blockage in one or more nozzles. Some blockages reduce or even prevent liquid from being emitted from printhead nozzles while other blockages can cause a stream of liquid jetted from printhead nozzles to be randomly directed away from its desired trajectory. Regardless of the type of blockage, nozzle blockage is deleterious to high quality printing and can adversely affect printhead reliability. This becomes even more important when using a page wide printing system that accomplishes printing in a single pass. During a single pass printing operation, usually all of the printing nozzles of a printhead are operational in order to achieve a desired image quality. As the printing system has only one opportunity to print a given section of media, image artifacts can result when one or more nozzles are blocked or otherwise not working properly.
As such, there is an ongoing need for better filtration of the liquid supplied to the nozzles of a printhead.